One object is to provide a hydraulic pump that allows a drive source to be started with a small torque. The hydraulic pump includes: a cylinder block having a plurality of cylinder bores and disposed so as to be rotatable; pistons each retained in associated one of the cylinder bores so as to be movable; a swash plate for controlling the amount of movement of the pistons in accordance with the size of the tilt angle; a first pressing unit for pressing the swash plate in such a direction as to reduce the tilt angle of the swash plate; and a second pressing unit for pressing the swash plate in such a direction as to increase the tilt angle of the swash plate by the pressure supplied from the outside.

A pump system (120) has a central pump unit (110), with which at least one hook-up unit (130). The least one hook-up unit (130) is from a group of a plurality of hook-up units (130) that can be combined in modular form for setting an operating point of a pump (10) that forms the pump unit (110). A method uses such a hook-up unit (130) in a pump system (120) for setting an operating point of the pump unit (110) thereof. A medical device is provided with such a pump unit (110) or with such a pump unit (110) and at least one hook-up unit (130) combined with the pump unit (110).

A hydraulically operated compressor has a fixed piston and a fixed compression or outer cylinder. A drive or intermediate cylinder is located between the piston and outer cylinder. A compression chamber is formed between the drive cylinder and the outer cylinder. Drive fluid is pumped into and released from an interior chamber in the drive cylinder to reciprocate the drive cylinder. The drive fluid also provides cooling to the interior of the compressor.

A swash-plate type piston pump includes a cylinder block configured to be rotated with rotation of a driving shaft, a plurality of pistons accommodated in a plurality of cylinders provided in the cylinder block, a swash plate configured to reciprocate the piston so that a volume chamber of the cylinder is expanded/contracted with the rotation of the cylinder block, an biasing mechanism configured to bias the swash plate in a direction where a tilting angle is made larger, a control pin configured to drive the swash plate in a direction where the tilting angle is made smaller in accordance with a rise in a load pressure of a pressure chamber, and a discharge channel configured to discharge the load pressure of the pressure chamber.

A swash-plate type piston pump includes a cylinder block configured to be rotated with rotation of a driving shaft, a plurality of pistons accommodated in a plurality of cylinders provided in the cylinder block, a swash plate configured to reciprocate the piston so that a volume chamber of the cylinder is expanded/contracted with the rotation of the cylinder block, an biasing mechanism configured to bias the swash plate in a direction where a tilting angle is made larger, a control pin configured to drive the swash plate in a direction where the tilting angle is made smaller in accordance with a rise in a load pressure of a pressure chamber, and a discharge channel configured to discharge the load pressure of the pressure chamber.

Described are a compressor driving apparatus and a refrigerator including the same. The compressor driving apparatus includes: switching elements; an inverter; an output current detector for detecting an output current flowing through a motor; and an inverter controller for controlling the inverter. The inverter controller controls the piston so that one end of the piston is fixed at a first position spaced apart from the discharge unit at stroke of the piston during a first period, controls the piston to collide with the discharge unit when a change rate in an operation rate or a position error of the compressor is equal to or greater than a predetermined value, and controls the piston so that the one end of the piston is fixed at a second position spaced apart from the discharge unit at stroke of the piston during a second period after the collision of the piston.

Described are a compressor driving apparatus and a refrigerator including the same. The compressor driving apparatus includes: switching elements; an inverter; an output current detector for detecting an output current flowing through a motor; and an inverter controller for controlling the inverter. The inverter controller controls the piston so that one end of the piston is fixed at a first position spaced apart from the discharge unit at stroke of the piston during a first period, controls the piston to collide with the discharge unit when a change rate in an operation rate or a position error of the compressor is equal to or greater than a predetermined value, and controls the piston so that the one end of the piston is fixed at a second position spaced apart from the discharge unit at stroke of the piston during a second period after the collision of the piston.

A system for cooling a storage area of a vehicle includes one or more eutectic plates (102) for cooling the storage area (101); a refrigeration system (103) configured to cool the one or more eutectic plates (102); an electrical system (106) configured to receive electrical power from a mains power supply and supply electrical power to the refrigeration system (103); a variable displacement hydraulic pump (113) having an input shaft for being driven by an engine (112) of the vehicle (100); and a generator (107) configured to receive hydraulic fluid from the hydraulic pump (113), generate electrical power in response thereto and supply the electrical power to the refrigeration system (103); the hydraulic pump (113) is configured to reduce the volume of hydraulic fluid that it supplies to the generator (107) for each rotation of the input shaft, as the rotational speed of the input shaft increases.

A system for cooling a storage area of a vehicle includes one or more eutectic plates (102) for cooling the storage area (101); a refrigeration system (103) configured to cool the one or more eutectic plates (102); an electrical system (106) configured to receive electrical power from a mains power supply and supply electrical power to the refrigeration system (103); a variable displacement hydraulic pump (113) having an input shaft for being driven by an engine (112) of the vehicle (100); and a generator (107) configured to receive hydraulic fluid from the hydraulic pump (113), generate electrical power in response thereto and supply the electrical power to the refrigeration system (103); the hydraulic pump (113) is configured to reduce the volume of hydraulic fluid that it supplies to the generator (107) for each rotation of the input shaft, as the rotational speed of the input shaft increases.

A pneumatic exomuscle system and methods for manufacturing and using same. The pneumatic exomuscle system includes a pneumatic module; a plurality of pneumatic actuators each operably coupled to the pneumatic module via at least one pneumatic line, a portion of the pneumatic actuators configured to be worn about respective body joints of a user; and a control module operably coupled to the pneumatic module, the control module configured to control the pneumatic module to selectively inflate portions of the pneumatic actuators.